How do I view postfix logs?

Postfix logs all failed and successful deliveries to a logfile. The file is usually called /var/log/maillog or /var/log/mail ; the exact pathname is defined in the /etc/syslog.

How do I check postfix mail in Linux?

To find out the version of postfix mail system running on your system, type the following command on the terminal. The -d flag enables displaying of default parameter settings in /etc/postficmain.cf configuration file instead of actual settings, and mail_version variable stores the package version.